Migration-resistant fat composition and nut-flavored filling using said fat composition

The present invention relates to a migration-resistant fat composition. More particularly, it relates to a migration-resistant fat composition that is useful as an ingredient of cream preparations, particularly containing a large amount of nut paste, to be put into the chocolate center or to be sandwiched between two pieces of baked confectionery such as biscuits and cookies. The present invention also relates to a nut-flavored filling using the migration-resistant fat composition.

Among the ingredients of cream preparations to be put into the chocolate center or to be sandwiched between two pieces of baked confectionery such as biscuits and cookies, there has hitherto been widely used nut paste as a flavoring material. When nut paste having a high oil content is used at large amounts, however, low-melting fat ingredients contained in the paste (e.g., at least 95% of almond oil is composed of oleic acid and linoleic acid) will migrate in the chocolate layer or in the baked cereal layer, thereby causing the deformation of products as well as the quality deterioration such as a change in the quality and a change in the sense of eating.

To eliminate these defects, various attempts have been made; for example, (a) high-melting fractions of unhydrogenated palm oil are mixed with peanut butter to prepare a cream preparation (see, e.g., JP-A 50-71865) and (b) a mixture of hydrogenated palm oil and peanut oil is added to a cream preparation (see, e.g., JP-A 53-139748). For use in nut-flavored fillings, however, satisfactory effects cannot be obtained. In particular, method (a) gives the flavor of peanut to the cream composition; therefore, its applications are inevitably restricted to the production of peanut-flavored confectionery.

Under these circumstances, the present inventors have intensively studied to develop a migration-resistant fat composition. As the result, they have found that a fat composition having specified physicochemical properties can suppress the fat migration and exhibit excellent melting properties in a mouth, even when nut paste having a high oil content is used as a major ingredient of cream preparations to be put into the chocolate center or to be sandwiched between two pieces of baked confectionery, thereby completing the present invention.

Thus, the present invention provides a migration-resistant fat composition characterized in that it has an iodine value of 35 to 60; a trans acid content of 30% to 50%; a melting point of 40° C. to 55° C.; a solid fat content of not less than 85% at 20° C.; not less than 60% at 30° C., not less than 30% at 40° C., and not more than 3% at 50° C.; and a trans acid/saturated fatty acid content ratio of 0.5 to 2.0.

Also provided is a nut-flavored filling characterized in that it comprises 5% to 20% migration-resistant fat composition as recited above and at least 20% nut paste having a fat content of at least 40%, the total content of the fat composition and the nut paste being not greater than 100%.

FIG. 1 is a schematic sectional view of a metal ring placed on a sheet of filter paper, which is used for the fat migration test.

FIG. 2 is a perspective view of a shell chocolate used for the preservation test, the chocolate being vertically cut into two parts for the purpose of showing the chocolate center.

FIG. 3 is a series of sectional views of the shell chocolate showing a change in its shape (i.e., depression ) observed during the preservation test.

The migration-resistant fat composition of the present invention can be produced by the elaidinization of a liquid fat with a catalyst, and if necessary, by the subsequent fractionation or the blending of at least two fractionated oils, so as to have an iodine value of 35 to 60; a trans acid content of 30% to 50%; a melting point of 40° C. to 55° C.; a solid fat content of not less than 85% at 20° C.; not less than 60% at 30° C., not less than 30% at 40° C., and not more than 3% at 50° C.; and a trans acid/saturated fatty acid content ratio of 0.5 to 2.0. In particular, it is preferred that the solid fat content is not less than 90% at 20° C., not less than 70% at 30° C., not less than 35% at 40° C., and not more than 3% at 50° C., because the fat composition can exhibit excellent characteristics in which the suppression of fat migration and the melting properties in a mouth are harmonized with each other. Here, the term "acid content", as used in "trans acid content" and "trans acid/saturated fatty acid content ratio", means the content of constituent fatty acids or acid residues, not free fatty acids, in the fat composition.

Examples of the liquid fat are palm oil, rapeseed oil, soybean oil, corn oil, cotton seed oil and rice bran oil. These liquid fats can be used solely or in combination. Examples of the catalyst are sulfur-poisoned nickel catalysts, and ordinary nickel catalysts combined with sulfur-containing amino acids such as methionine, S-adenosilmethionine, cysteine or glutathione; biotin; sulfur-containing vitamins such as thiamine; or natural isothiocyanate compounds such as aryl mustard seed oil.

When the solid fat content is less than 85% at 20° C., satisfactory migration resistance cannot be attained, and the fat composition will tend to migrate to the covering chocolate or to the dough for baked confectionery. To the contrary, when the solid fat content exceeds 3% at 50° C., the melting properties in a mouth will become deteriorated, so that a sense of incongruity is given to the material in the chocolate center.

Also when the trans acid content is less than 30% and the trans acid/saturated fatty acid content ratio is less than 0.5, the same disadvantages will occur on the melting properties in a mouth, as described for the solid fat content. To the contrary, when the trans acid content exceeds 50% or the trans acid/unsaturated fatty acid content ratio exceeds 2.0, satisfactory migration resistance cannot be attained. The trans acid content is preferably in the range of 33% to 50%.

The migration-resistant fat composition of the present invention is preferably used as an ingredient of nut-flavored fillings (e.g., nut paste-containing cream preparations). The nut paste can be prepared, for example, by roasting high oil content nuts and then by braying the roasted nuts into a paste form with a known means of braying, such as a triple roll mill. Examples of the high oil content nuts are peanuts, almonds, cashew nuts, hazelnuts, pistachio nuts, macadamia nuts, pecan nuts, and walnuts. The nut paste thus obtained has an oil content of about 50% to 60% on an average, with the maximum oil content amounting to 75% when pecan nuts are used.

The nut-flavored filling of the present invention can be produced by blending 5% to 20% migration-resistant fat composition and at least 20% nut paste having a fat content of at least 40% with a base material consisting of sugar, powdered milk, and if necessary, other ingredients.

When the amount of fat composition is less than 5%, fat migration cannot be satisfactorily suppressed. To the contrary, when the amount thereof exceeds 20%, the melting properties and the sense of eating will become deteriorated.

The migration-resistant fat composition of the present invention has a high melting point of 40° C. to 55° C., although it has a stearic acid content of 35% or less. The fat composition has a high content of trans acids (mainly, trans-9-octadecenoic acid or elaidic acid having a melting point of 44° C. to 45° C.) and it does not contain a large amount of trisaturated fatty acids as the case of extremely hardened rapeseed oil; therefore, the melting properties in a mouth are scarcely inhibited. It is also possible to improve the heat resistance and to suppress the fat migration by addition of the migration-resistant fat composition at small amounts.

The present invention will be further illustrated by way of the following examples, which are not to be construed to limit the scope thereof.